Software-defined radio (SDR) is an emerging concept that leverages the design of software-defined and hardware-independent signal processing chains for radio communication. It introduces flexibility to wireless systems, facilitating the dynamic switch from one radio access technology to another or, in other words, the de- and reallocation of computing resources from one SDR application to another. This paper introduces an SDR computing resource management framework. It accounts for several SDR system characteristics, including real-time computing requirements, limited computing resources, and the use of heterogeneous multiprocessor plat-forms, including multiprocessor systems-on-chip. The framework features the tw-mapping, a dy-namic mapping algorithm that is apt for many cost functions and, thus, adaptable to any radio scenario. The cost function proposal dynamically manages the available computing resources to satisfy the given SDR computing constraints. Two relevant SDR scenarios and the corresponding simulations, based on representative SDR platforms and processing chains, demonstrate the framework?s importance and suitability for software-defined radios.